Planta

, Volume 130, Issue 2, pp 159–167

Studies on the biochemistry and fine structure of silica shell formation in diatoms

Division cycle and chemical composition of Navicula pelliculosa during light-dark synchronized growth
  • W. M. Darley
  • C. W. Sullivan
  • B. E. Volcani
Article

DOI: 10.1007/BF00384414

Cite this article as:
Darley, W.M., Sullivan, C.W. & Volcani, B.E. Planta (1976) 130: 159. doi:10.1007/BF00384414

Summary

Cell division in Navicula pelliculosa (Bréb.) Hilse, strain 668 was synchronized with an alternating regime of 5 h light and 7 h dark. Cell volume and dry weight increased only during the light period. DNA synthesis, which began during the third h of light, was followed sequentially by mitosis, cytokinesis, silicic acid uptake, cell wall formation, and cell separation. Silicification and a small amount of net synthesis of DNA, RNA and protein occurred during the dark at the expense of carbohydrate reserves accumulated during the light period. Cells kept in continuous light, after synchronization with the light-dark regime, remained synchronized through a second division cycle; the sequence of morphological events was the same as that in the light-dark division cycle, but the biosynthesis of macromolecular components changed from a stepwise to a linear pattern. The silicon-starvation synchrony was improved by depriving light-dark synchronized cells of silicic acid at the beginning of their division cycle, then resupplying silicic acid to cells blocked at wall formation.

Abbreviation

L

light

D

dark

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • W. M. Darley
    • 1
  • C. W. Sullivan
    • 1
  • B. E. Volcani
    • 1
  1. 1.Scripps Institution of OceanographyUniversity of CaliforniaLa JollaUSA
  2. 2.Department of BotanyUniversity of GeorgiaAthens
  3. 3.Department of Biological SciencesUniversity of Southern CaliforniaLos Angeles

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